Need Help making the following circuit

[rabbit]

I want to build a physical pressure sensor that detects pressure and
transmits this information to a recording device (watch?). Proposed
application: If one wants to know how many times and length of time
that someone sits on a chair, this device (attached to the backside of
the person) would be able to give that information.
Thank you for your expertise.

 

[D from BC]

I want to build a physical pressure sensor that detects pressure and
transmits this information to a recording device (watch?). Proposed
application: If one wants to know how many times and length of time
that someone sits on a chair, this device (attached to the backside of
the person) would be able to give that information.
Thank you for your expertise.

Goofy answer:
It's called a flight data recorder..Or black box..
But seriously...
I gotta question from the question ...
Isn't there some sort of proximity detection method using field coils
or antenna? Dodges pressure sensor idea..

Is the person at a computer?...could just interface and software it.
D from BC

 

[rabbit]

Thanks for responding D. Unfortunately my background in electrical
engineering is VERY LIMITED. WHat do you mean by "proximity detection
method using field coils or antenna" ?
What I was looking for was a small device that could be attached to a
mobile human being (maybe attached to a belt) and record the duration
of time that person is in only that position. I appreciate any further
input.

 

[D from BC]

Thanks for responding D. Unfortunately my background in electrical
engineering is VERY LIMITED. WHat do you mean by "proximity detection
method using field coils or antenna" ?
What I was looking for was a small device that could be attached to a
mobile human being (maybe attached to a belt) and record the duration
of time that person is in only that position. I appreciate any further
input.

That's kinda like the opposite of a pedometer.
See
http://en.wikipedia.org/wiki/Pedometer
http://search.ebay.com/pedometer_W0QQfkrZ1QQfromZR8QQsubmitsearchZSearch
Maybe hack one of those things and turn it into a position- o- meter?
Just guessing..
D from BC

 

[Jan Panteltje]

I want to build a physical pressure sensor that detects pressure and
transmits this information to a recording device (watch?). Proposed
application: If one wants to know how many times and length of time
that someone sits on a chair, this device (attached to the backside of
the person) would be able to give that information.
Thank you for your expertise.

Chewing gum?

 

[mpm]

I want to build a physical pressure sensor that detects pressure and
transmits this information to a recording device (watch?).

You really don't need a pressure "sensor". A pressure "switch" will
suffice.
Take a look at the the World Magnetics products (avail from Digikey).
These have 2 connections, which form a closed circuit when the pressure
exceeds a predetermined value. Some models have adjustable trip
points. These switches require no electricity to operate.

Digikey #: 384-1019-ND, for example.

-mpm